Manual

13
BASEPLATE
SELF-LUBRICATED TYPE COMPRESSORS
Install oil pump piston and rod on crankshaft.
Oil rod bearing fit must be the same as specified for
connecting rod bearings. Install oil rod cap nuts and cotter
pins to lock oil rod nuts.
Install oil pump relief valve in base plate. The relief valve can
be tested at this stage by applying air pressure to the relief
valve. The valve should open when the pressure is between
14 psi minimum and 24 psi maximum. When the relief valve
is properly installed in the base plate, install set screw that
locks it in place.
Place oil pump screen in base and install retaining ring,
making sure it snaps in place and secures the screw.
Install oil filter fitting on base plate in its proper place. Install
blanking cover on opposite oil filter fitting hole in plate.
Install a new oil seal gasket around oil pump - check valve
and position a new base plate gasket on the crankcase.
Position base plate assembly on crankcase, making sure
oil pump piston engages the oil pump bushing in the base
plate. Install and tighten base plate screws.
TESTING REBUILT COMPRESSOR
In order to properly test a compressor under operating
conditions, a test rack for correct mounting, cooling,
lubricating and driving the compressor is necessary. Such
tests are not compulsory if the unit has been carefully rebuilt
by an experienced person.
A compressor efficiency or build-up test can be run which is
not too difficult. Before the test, the crankcase of a self-
lubricated type compressor should be properly filled with
lubricating oil. An engine lubricated compressor must be
connected to an oil supply line of at least 15 pounds pressure
during the test and an oil return line must be installed to
keep the crankcase drained. The compressor (when tested)
should be tested without a strainer.
To the discharge port of the compressor, connect a reservoir
or reservoirs whose volume plus the volume of the connecting
line equals 1,300 cubic inches. Run the compressor between
1,700 and 1,750 RPM. Elapsed time that the compressor
takes to build up from 0 to 100 psi depends on the type
compressor as follows:
BUILD-UP TIME
TYPE COMPRESSOR 0 TO 100 PSI
TU-FLO
®
400 47 SECONDS MAXIMUM
TU-FLO
®
500 30 SECONDS MAXIMUM
TU-FLO
®
1000 15 SECONDS MAXIMUM
During the above test the compressor should be checked
for oil leakage and noisy operation.
COMPRESSOR TROUBLESHOOTING
IMPORTANT: The troubleshooting contained in this section
considers the compressor as an integrated component of
the overall air brake charging system and assumes that an
air dryer is in use. The troubleshooting presented will cover
not only the compressor itself, but also other charging system
devices as they relate to the compressor.
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
FIGURE 26 - AIR STRAINER - EXPLODED VIEW
AIR STRAINER
If the compressor is type with air strainer, assemble strainer
(Fig. 26). Using a new strainer gasket, install strainer on
cylinder block.
GOVERNOR
If compressor is type with pad mounted governor, install a
new or factory rebuilt governor using a new governor gasket.
INSPECTION OF REBUILT UNIT
Check to be sure that covers, plugs or masking tape are
used to protect all ports if compressor is not to be installed
immediately.
Fit the end of all crankshafts with keys, nuts and cotter pins
as required and then protect the ends against damage by
wrapping with masking or friction tape.
The open bottom of engine lubricated compressors should
be protected against the entrance of dirt during handling or
storage, by installing a temporary cover over base.